Mechanisms during laser bending (2008)
In order to investigate the thermomechanical phenomena during the laser bending process, a simulation is performed. The governing thermoelastic-plastic equations are integrated by the finite element...
Heizvorrichtung fuer eine Turbinenschaufel und ein Verfahren zum Schweissen (2008)
Burbaum, B., Mokadem, S., Pirch, N.
WO 2009098106 A1 UPAB: 20090824 NOVELTY - The heating loop (41) used in the new turbine blade heating unit is seen to be generally U-shaped, with intentional additional curvatures. Its arrangement is...
Cladding, drilling, and shaping of aerospace and power plant components by laser radiation (2004)
Kreutz, E.W., Willach, J., Kelbassa, I., Backes, G., Horn, A., Keutgen, S., ...
Drilling of cooling holes (diameter about 200µm) in a multilayer system (CMSX-4, MCrAlY, zirconia) of turbine blades enabling effusion cooling is performed via melt extraction by pulsed laser...
Wissenbach, K., Willenborg, E., Pirch, N.
WO2004003239 A UPAB: 20040202 NOVELTY - The smoothing and polishing method has continuous or pulsed laser radiation with a pulse duration of greater than 100 microseconds used for an initial...
Drenker, A., Baumann, M., Pirch, N., Sommer, J., Vitr, G., ...
Warpage is a problem that frequently occurs in laser transformation hardening of precision parts. If, for example, the ball bearing tracks of a linear guiding rail are sequentially hardened with a...
Keutgen, S., Backes, G., Kreutz, E.W., Pirch, N.
Durch Legieren mit Nd:YAG Laserstrahlung wird unter der Bedingung der schnellen Erstarrung (DeltaT/Delta t>103K/s) die für tribologische Anwendungen typische Aluminiumlegierung AI4.5ZnMgPbSiCu der...
Front tracking thermomechanical model for transient stresses during laser welding (2002)
A thermo-elasto-plastic stress analysis of transient conduction-mode pulsed laser welding is performed with the Finite Element Method. The investigation focus on the degree of dependence of resulting...
Kelbassa, I., Gasser, A., Backes, G., Keutgen, S., Kreutz, E.W., Pirch, N.
Closed-center process chain and an on-line temperature control for turbine component repair were validated. Laser cladding on turbine components by CO2 and Nd:YAG laser radiation is carried out using...
Effect of beam width on melt characteristics in large-area laser surface alloying (2001)
Liu, Z., Pirch, N., Gasser, A., Watkins, K.G., Hatherley, P.G.
This article presents an investigation of the convection behavior of the melt pool for laser surface alloying with a wide beam. A line beam source with a dimension of 6 mm x 0.7 mm from a 3 kW cw...
Simulation of micro-channel heat sinks for optoelectronic microsystems (2000)
Kreutz, E.W., Pirch, N., Ebert, T., Wester, R., Ollier, B., Loosen, R., ...
Water-cooled heat sinks are investigated both experimentally and theoretically as model systems to simulate the energy and mass transport in devices used for cooling of optoelectronic microsystems....
The development of solute distribution at dendritic interface for one step laser surface alloying /3/ is investigated by numerical simulation. The dendritic mushy zone is approximated by columnar...
Minimum time for laser induced amorphization of Ge2Sb2Te5 films (2000)
Weidenhof, V., Pirch, N., Friedrich, I., Ziegler, S., Wuttig, M.
Wissenbach, K., Pirch, N., Schürmann, B., Vitr, G.
In den letzten Jahren konnten an zahlreichen Beispielen die technologischen Vorteile des Lasestrahlhärtens demonstriert werden. Für eine Umsetzung in die industrielle Fertigung waren jedoch...
Erhöhung der Umformbarkeit von Halbzeugen durch lokale Rekristallisation mit Laserstrahlung (1996)
Maischner, D., Wissenbach, K., Pirch, N., Luft, A., Emsermann, A., Hoppe, M.
In diesem Beitrag werden verfahrenstechnische Grundlagen zum Rekristallisieren eines Halbzeuges (Metallband) mit Laserstrahlung vorgestellt. Ziel ist es dabei, die Umformbarkeit des Materials zu...
Ein numerisches Modell zum einstufigen Laserstrahlbeschichten (1995)
Ollier, B., Pirch, N., Kreutz, E.W.
Laser cladding is a method to deposit coatings on surfaces, that enable an improvement of the chemical and tribological resistance by hardfacing. Theoretical and experimental results for the...
Laser surface alloying of metallic materials (1995)
He, X., Pirch, N., Kreutz, E.W., Mordike, B.L.
In this paper the development of a two dimensional model is described for one step laser surface alloying. The temperature, flow and concentration fields in the longitudinal section are calculated...
Hoogvermogenlasers voor thermisch behandelen van oppervlakken. Tl.2 (1993)
Barkhausen, W., Gasser, A., Küpper, F., Vitr, G., Wehner, M., Wissenbach, K., ...
Hoogvermogenlasers voor thermisch behandelen van oppervlakken. Tl.1 (1993)
Barkhausen, W., Gasser, A., Küpper, F., Vitr, G., Wehner, M., Wissenbach, K., ...
Surface remelting and alloying of Al-based alloys with CO2 laser radiation (1992)
Kreutz, E.W., Rozsnoki, M., Pirch, N.
Surface remelting and alloying with CO2 laser radiation of aluminium (Al99.99) and Al-based alloys (AlSi10Mg) are investigated as a function of processing variables. Cr and Ni have been used as...
Melt dynamics and solidification in surface processing with laser radiation (1992)
Kreutz, E.W., Ollier, B., Pirch, N.
2- and 3-dimensional self consistent modelling calculations of the surface-tension driven melt dynamics with flat and free surfaces are presented as a function of processing variables for surface...
Laser surface alloying of Al99.99 and AlSi10Mg with Cr and Ni (1992)
Kreutz, E.W., Pirch, N., Rozsnoki, M.
The surfaces of Al99.99 and AlSi10Mg are alloyed with laser radiation using Cr and Ni which are blown into the melt pool within the interaction zone by powder feeding technique. The alloyed zone was...
Umschmelzen von Aluminium-Gußlegierungen mit CO2-Laserstrahlung. (1991)
Backes, G., Kreutz, E.W., Ollier, B., Pirch, N., Rozsnoki, M., Gasser, A., ...
Im Vergleich mit konventionellen Methoden erlaubt Laserstrahlung durch definierte Wärmeeinbringung eine Oberflächenveredelung zu erreichen, ohne das restliche Bauteil zu beeinflussen. Weitere...
Melt dynamics in surface processing with laser radiation (1991)
Pirch, N., Kreutz, E.W., Möller, L., Gasser, A., Wissenbach, K.
The basic physical processes of melting with laser radiation are reported especially including the free self-adjusting surface. A three dimensional stationary model for the thermocapillary flow is...
Die Humping Instabilität beim Schweißen mit Laserstrahlung (1991)
Pirch, N., Schmidt, H., Ollier, B., Kreutz, E.W., Becker, D.
Theoretische Untersuchungen zur Umströmung der Dampfkapillaren beim Schweißen mit Laserstrahlung werden vorgestellt. Der lokale Wärmestrom auf der schmelz-/gasförmigen Grenzfläche wird in einem...
Surface melting of AlSi10Mg with Co2 laser radiation (1990)
Backes, G., Gasser, A., Kreutz, E.W., Ollier, B., Pirch, N., Rozsoki, M., ...
The melting of sandcast and chillcast AlSilOMg alloys with CO2 laser radiation is investigated as a fuction of processing variables to improve the surface properties with respect to wear resistance...
Momentum transfer of an inert gas jet to a free surface of a molten pool (1989)
Pirch, N., Schulz, W., Becker, D., Kreutz, E.W.
It can be said in summarizing, that, on the one hand, sensor technology is so far developed today that automatic fabric inspection can more than ever be regarded as feasible. In addition, the...